Power press



Npv. 24, 1925- 1,562,988

J- NELSON POWER P RESS Filed NOV. 1922 4 Shoots-Sheet 1 [Kw/armor;

{NovL 34, 1925.

J. NELSON 7 POWER PRESS Filed Nov, 2. 1922 4 Sheets-Sheet z Ewan-ton knJ? on, 0% m,

Nov. 24, 1925- 1 1,562,988

J. NELSON POWER PRESS Filed Nov. 2. 1922 4 Sheets-Shut 3 fie Pas ed N...24, 1925. i

" tum-.1 's'rA'r s i 1,562,988- PATENT. orrlcs.

Joan NELSON, or cnrcneo, rumors, ASSIGNOR- rdmnonnrrn r001. & MANUFAC.TURING COMPANY,- or cnrcneo, rumors, A conronn'rron or rumors.

rower.

PRESS.

Application filed November 2, 1922. Serial Ko. 598,698.

To all whom; it may concern:

Be it known that I, JOHN NELSON, a citizen of the United States, and aresident of Chicago, Cook County, and State of Illinois, have inventedcertain new and useful Tine provements in Power Presses, of-which the.following is declared to be a full, clear, and exact description.

This invention relates to power presses and one of its principal objectsis to provide pressure operated balancing means whereby the usual heavyfly wheel nay be dispensed with. Another object is to provide pressureoperated balancing means for the ram, which will enable the press to bebuilt with a lighter crank shaft than is required for a press of thesame capacity and power as one equipped withthe balancing meansembodying the present invention. Another object is to provide means forstoring up energy, (independent of the fly wheel) onthe up stroke of theram. Another object is to provide means for storing up energy on the upstroke of the ram, (independent of the fly wheel), and for deliveringsaid stored up energy to the ram on its down stroke, in lines parallelwith the direction of movement of the ram. Another object is to providemeans for storing up energy on the up stroke of the ram, (independent ofthe fly wheel), and for utilizing said stored up energy in conjunctionwith the usual crank shaft of the press.

This invention has been designed for use in connection with presseswhich employ draw-ring or blank holding mechanism'to apply pressure tothe marginal portions of the blank while the press is doing its work,and one of the objects of the present invention-is to provide improvedmeans for operating the draw-ring. In certain classes of work it isimportant that greater pressure be applied to the draw-ring at certainplaces than at others, and one of the objects of this invention is toprovide means for producing additional pressure uponthe drawring atanyone or more various places thereon as is desired. Other objects andadvantages will occur in the course of this specification, and with allof said objects and advantages inview, this invention consists in theseveral novel features hereinafter fully set forth and more particularlydefined in the appended claims.

The invention is clearly illustrated in the 65 accompanying drawings, inwhich:

Fig. l is a side elevation, partly broken out, of a power pressembodying a simple form of the present invention, showing the ram at thetop of its up stroke; Fig. l is a diagrammatic view of compressed airtanks used in connection with the press; Fig. 2 is a vertical crosssection of the press taken on the line 22 of Fig. 1, showing the ram atthe bottom of the down stroke;

Fig. 3 is a view, partly in plan and partly in horizontal section, theline of section being indicated at 33 in Fig. 1; Fig. 4 is a View,partly in under plan and partly in horizontal section, the line ofsection being indicated at 44 in Fig. 1; Fig. 5 is a detail, verticalsection of certain members of the draw-ring actuating means, the line ofsection being indicatedat 5-5 in Fig. 3; Fig. 6 is a view similarto Fig.5 but showing the parts in a different position; Fig. 7 is a detail,horizontal section taken on the line 7-7 of Fig. 5; Fig. 8 is a detail,horizontal section taken on the line 8-8 of Fig. 5'; Fig. 9 is avertical longitudinal section through a fragment of'a die pressillustrat ing'a modified form of draw-ring mechanism.

Referi'ng first to Figs. 1 to 8, inclusive,

which illustrate the preferred embodiment of the invention, thereference character 10 designates thebase, 11 the bed, 12- the bolsterand 13 the upright side frame members of a power press of ordinary andwell known construct-ion. Resting upon and secured to the bolster, isthe female die 14, and cooperating therewith is the punch or-male die15, which is secured to the ram 16 by bolts as is well understoed. Theram 16 is guided upon the side frame members 13 to move lengthwisethereof. Connectin rods 17 connect the ram 16 withthe cradks' 18 of thecrank shaft 19, as is well understood, and the crank shaft is journaledin bearing boxes 20 formed in the upper ends of the-side frame members13. A back geared press is illustrated in thedrawings, and as shown, the

crank shaft 19, is driven from a main drive I i shaft 21, by a pinion 22on the main drive shaft-.21, and a. gear wheel 23 on'the crank 1 5shaft, which gear wheel meshes with said pinion. Clutch mechanism ,(notshown) may be provided, as is customary for startabsorbed by thepressure operated balancing means employed in connection therewith.

It is also to be observed that the usual heavy fly wheel or balancewheel is dispensed with. Otherwise, the general construction of thepress proper is practically similar to that of the ordinary and wellknown die presses.

Secured to the arch bar 24 is a cylinder 1 25, closed at the top by acylinder head 26 and open at the bottom. In said cylinder 25 is apiston27, which is connected to the ram 16 by pistons rods 28, there being atleast one piston rod on each side of the crank shaft, extending throughlugs 29 formed upon an upwardly extending rib portion 30' of the ram.Lock nuts 31 threaded on the lower ends of said piston rods 28, on theopposite sides of the said lugs 29, rigidly connect the piston rods 28with the ram. On the up stroke of the ram, the piston 27 compresses theair in the cylinder 25, and on the down stroke of the piston, thecompressed air acts in conjunction with the crank shaft in forcing thepiston down during its working stroke. It will also be observed that thepower derived from the compressed air is exerted through the piston rods28, in lines parallel with the direction of movement of the ram.

It is preferred to maintain a constant sup sure may be had in'thereservoir and cylinder 25, with this arrangement, so that a practicallyuniform pressure may be had upon the piston 27 at all times. Moreover,with the use of the air pressure, as an aid 'to the crank shaft, lesspower need be employed for driving said crank shaft, and because of theapplication of the power from I the cylinder to the ram on linesparallel with the movement of the ram, the crank shaft may be made oflighter construction than usual in presses of this kind.

The invention has been shown in connection with a press employedin'drawing metal and as is customary, a draw-ring 34 is em ployed, whichdraw-ring conforms generally to the shape of the die 14, andsaiddraw-ring is bolted or otherwise secured to' a draw-ring plate 35.The draw-ring 34 and draw-ring plate 35 have openings 34" therethrough,for the punch on d1e 15. The draw-ring plate 35 is carried by a pluralitof stems or -rods 36, which have. reduce portions 36 that extend throughthe draw-ring plate 35, and are secured thereto by nuts 36, threaded onthe upon their upper ends. When in the position seen in Fig. 1, thepistons or plungers 38 rest upon the upper face of the ram 16 andsupport the draw-ring late and draw-' ring above the die 14 throng theinstrumentality of the stems or rods 36. 4

The pistons 38 are contained in cylinders 39, bolted orotherwise securedto the ram 33, and located in each cylinder, above the piston 38 is astati'onarily supported circular or disk like block 40, that forms theupper head of the cylinder 39. Said stationary heads 40 are supportedby, and rigidly fastened-to head supporting members 41 which are shownin the formof tubular members that are rigidly connected with the archbar 24 and project down therefrom. As shown, the ,upperends of thetubular members are reduced to provide shoulders that bear against theunder sides and have pistons or plungers 38 secured of the arch bar, andthreaded on the upper ends of said tubular members are nuts 42, thatbear against the upper side of the arch bar. A regulatablc andsubstantially constant supply of compressed air is maintained in thecylinders 39 between the heads 40 and pistons 38 and for this purpose anair reservoir 43 is provided which communicates with a pipe 43 andbranches 43* that lead into'the upper ends of said tubular headsupporting members 41.. It will be observed that by reason of the airpressure on the tops of the pistons 38, the draw-ring, when it islowered into contact with the wprk, is held in pressing contacttherewith, which pressure is maintained substantially constant duringthe time that the punch .or die 15 is performing its work. i

In the work of drawing certain shapes, it is sometimes necessary toplace greater pressure upon certain parts of the marginal portions ofthe blank than upon others so' as to prevent those portiorrsof the blankfrom being drawn down out of 'sha e, and improved means have been proviedfor applying additional pressure at a plurality pressure devices areemployed.

duced portions 46 which extend through the draw-ring plate and have nuts46* threaded upon their lower threaded ends. The cylinders 44 containwateig'oil or other liquid-above'the pistons 45, and regulatable nieansare provided for affording restricted or unrestricteddischarge passagesfrom the cylinders 44 whereby when pressure is applied to the liquidcontents of the cylinders containing the restricted discharge passages,said contents may escape comparatively slowly, and at a pre-determinedflow so as to maintain a substantially constant pressure against thepistons 45, there being means for permitting the liquid to freelyreenter the cylinders upon the outward strokes of the pistons. In theembodiment of the invention illustrated, each cylinder 44 has apartition or a head 46 at its upper end, in which is one or more ports47 through which the liquid contents may pass in either direction. Theseports are shown in arcuate form'in Fig. 7. Below eachhead or partition46 1S a valve member, here shown in the form of a disk 48, (see Fig. 8)

which also is provided with arcuate ports 49, which 111.9118 positionmay coincide with the ports of the head or partition 46, to.

obtain a discharge port of maxmum area, but by turning the valve disk48, the solid portions thereof may be caused to overlap the ports 47 of,the head 46 so as to decrease the area of said ports 47 to any degreedesired, thereby decreasing the size of the discharge orifice ororifices from the cylin.

1 der 44, and determining the amount of pressure on the piston in thecylinder. As shown, each valve disk 48 is mounted upon a valve stem 50which extends up through a central orifice in the head 46 and isconnected to a hand lever 51 by means of which the valve disk 48 may beturned to regulate the area of the discharge orifices. Upon the upperend of the valve stem 50 is secured a sleeve 52 by a pin or otherwise,and a stem 53, secured to the hand lever 51, enters said sleeve 52 andhas a sliding connection there with, but is non-rotatively connectedthereto, as for instance, by a pin 54 that is secured in the stemand-enters vertical slots in the sleeve 52. The valve disk 48 normallyseats against the lower face of the head 46 and it held inseatingengagement therewith by a coiled compression spring 56 which isinterposed between the upper face of the head 46 and the lower end ofthe sleeve 52. The upper end of the stem 53 is mountedin a bearing 57supported by arms 58 that extend from the wall 59 of a chamber above thecylinder 44 into which the liquid is-forced by the action of the piston45, and said Wall 59 may, if desired, be a continuation of I the wall ofthe cylinder- 44. For holding the head lever 51 at any pie-determinedposition, a tooth segmental rack (30 may be provided upon the upper endof the annular wall 59 with which engages a tooth (31 on the hand lever.

In the operation of the power press described, a metal blank indicatedat A n Fig. 2 is placed upon the lower die 14, while the ram 16 is atthe top of its up stroke. The draw-ring 34 is now suspendedfrom therain, and the pistons 38 that carry the draw.- ring plate, ders 39. Asthe crank shaft 19 is revolved, the ram 16 is moved downward, carryingbefore it the draw-ring 34, and the air pressure upon the piston 27 inthe cylinder 25 cooperates with the crank shaft, to apply force to thepunch or die 15 during the working stroke 'of the press. Before thepunch engages the blank, the draw-ring has come into contact with themarginal portions thereof. as seen in Fig. 2, and is thereupon held if:pressing engagement with the blank by the action of the compressed airin the cylinders. 39 on the tops of the pistons 38. As the ram 16continues its downward working stroke,

above are under pressure in the cylinand draw-ring 34. The pressure onthe.

draw-ring remains substantially constant punch or die 15 is the blank. I

During the up stroke of the ram, the punch or die 15 is raised, and assoon as the ramenperforming its work on gages the lower faces of thepistons 38, it

lifts said pistons, and therewith the draw ring plate, and draw-ring,thereby raising it above the lower die 14. \Vhen the auxiliary orhydraulic pressure devices are used, or when one or more of them is usedfor ekerting greater pressure upon the blank at certain'places thereon,the

during the entire interval of time that the valve disk 48 of eachworking cylinder 44,

which is to be used, is set to regulate the area of the dischargeorifices of that cylinder.

Duringthe first portion of the down stroke of the ram, the pistons 45inall. ofthe cylinof the rods 36*.

ders 44 travel down with the ram, and cylinders, but as soon as the draw-ring encounters the blank, the movement of the pistons is arrestedalthough the cylinders 44 continue their downward movement during theremainder of the down stroke. The result is that the liquid in theworking cylinders 44 is displaced slowly through the restricted portstherein, and'pressure is thereby put upon the tops of the pistons -15 ofsaid working cylinders, whereby additional pressure is produced upon theblank under said working cylinders. Those portions of the blank arethereby held more firmly between the drawring and lower die than otherportions of the blank. This pressure upon the blank is maintainedconstantly until the ram reaches the lower end of its down stroke and onthe up stroke of the ram the cylinders 44 are lifted with .the rain,thereby increasing the distance between the pistons 45 and heads 46,whereupon, the valve disks '48 are unseated, ermitting the liquid torapidly reenter the lnteriors of the pistons 44. It is to be understoodthat the chambers above the pistons 44 should be of suflicient capacityto contain all of the liquid which is displaced in the associatedcylinder 44.

In the modified form of the invention illustrated in Fig. 9, in place ofusing a fluid for placing pressure upon the draw-ring 344, springpressure is utilized. In this form of the invention, shouldered rods 36are disposed about the dies and extend through the ram 16, draw-ring 34and bolster 12. The rods-36" have heads or shouldered portions 36 attheir upper ends which rest upon the ram, and shouldered-portions 36therebelow which are adapted to engage with the upper face of thedraw-ring 34. The rods also have shouldered portions 36 below the drawring, which are adapted to engage with the lower side thereof. Thisarrangement provides means wherebythe rods 36 have a limited amount ofplay with respect to the draw-ring and with respect to the ram. Springpressure is applied to the draw-ring by coiled compression spring 36confined under pressure between some member of the press, as forinstance, the bolster, and a cross bar 36 which is. held upon the rods 3r by nuts 36, threaded on the lower ends In the operation of this formof the invention, the draw-ring is held up above the lower die 14 by theshoulders 36 of the rods 36", the rods being normally held upwardagainst the action of the springs 36 by the engagement ofthe ram 16 withthe heads 36 of the rods. As theram descends,

'the'coiled compression springs force the rods 36? downward,ftherebylowering the draw-ring upon the'work, and as the ram continues todescend, it leaves the heads 36, thereby permitting the coiledcompression springs to draw the shoulders 36 of the rods against theupper side of the drawring, thereby placing pressure upon the. blankheld between the draw-ring and the lower die. During the up stroke ofthe ram,

the draw-ring is held down until the ram' engages the heads 36 of therods 36 and lifts the latter and therewith the draw-ring.

While the invention has been illustrated in connection with a die pressfor drawlng metal, it is not the intention of the inventor to limit theinvention thereto, as it is applicable to various types of powerpresses.

From the above it is to be observed that the compressed air cylinder atthe top of the press aids the crank shaft in its work and relieves it ofthe usual strain occasioned during its working stroke. Furthermore, thatwhen the draw-ring has been brought intov pressing engagement with thework, the pressure on the work remains constant through the. entireworking stroke of the press. Furthermore, that abnormal pressure may beobtained upon the work at any place or places around its marginalpgrtion and that the de ree of pressure may regulated tosuit tierequlrements.

More or less variation of the exact details of construction is possiblewithout departing from the spirit of this invention;

I desire, therefore, not to limit myself to regulating the pressure ineach pressure device.

2. In a ower press, in combination with its ram, 0 a draw-ring movablewith said ram into engagement with the work, compressed air cylindersmounted on said ram and istons in said cylinders connected with theraw-ring, non-compressible fluid pressure cylinders mounted on said ramhaving restricted discharge orifices leading therefrom, and pistons insaid cylinders connected with'the draw-ring.

3. In a power press, in combination with its ram, of a drawming, movablewith said ram into engagement with the work, comprest'ed air cyllndersmounted on said ram and pistons in said cylinders connected with thedraw-ring, non-compressible fluid pressure cylinders mounted on said ramhavingregulatable restricted discharge orifices leading therefrom, andpistons in said cylinders connected with the draw-ring.

4. In a power press, combination with its ram, of a draw-ring, movablewithsaid ram into en agement with the work, hydraulic cylinders mountedon said ram, said cylinders having regulatable restricted dischargeorifices leading therefrom, and pistons in said cylinders connected toSaid draw-ring. V

5. In a power press, in combination with its ram, of awork holdermovable with said ram into engagement with the work, a plurality ofhydraulic pressure devices connected to said work holder and means forregulating the pressure in each pressure device.

'6. In aower press, in combination with its ram, 0 a work holder movablewith said ram into engagement with 'the work, compressed air cylindersmounted on said ram and pistons in said cylinders connectedwith' thework holder, non-compressible fluid pressure cylinders mounted on saidram having restricted discharge orifices leading therefrom, and pistonsin said cylinders connected with the work holder..

7. In a power press, in combination with its ram, of a draw ring movablewith the ram into engagementwith the'work, a plurality of fluid pressuredevices connected to the draw ring, and means for regulating thepressure in each of the fluid pressure devices.

8. In a power press, in combination with its ram, of a draw ring movablewith the ram into engagement with the work, a plupressure in each of thefluid pressure devices independently, one with respect to the other. 9.In a power press, in combination with its ram, of a draw ring movablewith the ram into engagement with the work, a plurality of fluidpressure devices connected to the' draw ring, and means for regulatingthe ressu're in each of the fluid pressure devices lndependently, onewithv respect to the other, andat will. V 10. ha power press, incombination with its ram, of. a draw ring movable'with the ram intoengagement with the work, a. plurality of fluid pressure devicesconnected to the draw ring, and means for regulating thepressure. ineach of the fluid pressure devices.

11. In a power press, the combination with its ram, of draw-ringassociated with said ram and movable therewith into engagement with thework, fluid pressure cylinders mounted upon the ram, pistons, one ineach a cylinder connected with the draw-ring, and a compressed airreservoir communicating with said cylinder.

- JOHN NELSON.

